Hi guys im new here

i have a volvo 940 98' with b230fk and i installed a mbc into it, and i have a question about the boost pressure - stock one was about 0.3 bar (about 4 psi) like a normal fk, now it does at peak about 1 bar (20+ psi) and after it get to peak goes down back to stock, or very close to stock pressure, why is that?

and the mbc is fully closed (should be minimal boost) and if i open it it does the same just with higher peak pressure, maybe it is defaulted? what can be wrong with it? its just a simple "resistor".

edit: this is what i have - http://www.ebay.com/itm/UNIVERSAL-RE...70c0e9&vxp=mtr.

it came with a splitter as you can see so one hose goes to the wastegate and one to the mbc and and the second connection in the mbc isnt connected to anything, is it ok? this is how the shop did this.

 

anyone?

 

You'd get much better response at Turbobricks. Here, more of a stock maintenance fare... Plus you are overseas somewhere, lucky devil, (940 were done in the US by 1995)...

 

One side goes from the compressor housing, to the mbc, then to the waste gate.

I think the only reason the "splitter" is included in that is because it has a vent hole in that part. It's a bleeder type mbc.

Its not installed right. Look at the fist page on the 740 link in my sig how I hooked up mine.
and 1bar is only ~14.7psi. You will not see over 15 with stock ecus.

 

thanks for responding, you're right its 14.5 psi dont know why i tought its 20 somthing.. nvm.
Are you sure i can install the mbc i have without the splitter? (as you said its a bleeder type) or should i just get a new one?

 

I haven't used that one. So I'm not familiar with the inside of it. Or positioning of the adjuster.

IIRC, those ebay ones had the arrow backwards or something. Some guys on turbobricks would know better.
Mine had a small bleed hole on the side of it. The bleed hole is there to help with spiking. That's all really. You could try with out it. But do not hold me to that.

Anyways, installed, you should have the adjust part first, so the pressure push against the ball inside it. Then I would think the bleeder part is in-between the adjust and waste gate.
That is my thoughts on how it would make sense to install it.
I do not know why there is three ports on it. I've never looked at the instructions.

 

this is how it is connected... the ball is in the tee splitter

 

That is one of the dumbest thing I have seen. Why would they make it that way...

This is all it should be... Yoshifab.com - Manual boost controller
Here is what I have: TurboLogic Performance<SUP>TM</SUP> Model TL-21 MBC Kit
Find something like those and you'll be fine.
Adjusting the preload on the spring is how those work. no preload adjustment, no change from stock. That ebay one is weird... The adjuster is not controlling the spring? doesn't make any sense to me.